Understanding the Survey of Household Finances (EFF)

Background and Objectives

The Survey of Household Finances (Encuesta Financiera de las Familias – EFF) has been a cornerstone of economic analysis in Spain since its inception in 2002. Conducted by the Banco de España, this large-scale survey aims to provide a comprehensive overview of the economic and financial situations of households across the country.

The EFF serves as a vital resource for policymakers, offering detailed insights into households’ income, assets, debts, and spending habits. It also delves into employment status, insurance products, pension plans, and other critical aspects of household economics. By characterizing the financial positions of households, the EFF allows for a nuanced analysis of economic trends over time.

One of the survey’s most significant contributions is its role in shaping public policy. The data collected provides a robust evidence base that helps authorities formulate economic policies that are more aligned with the actual needs and financial realities of Spanish households. Recognizing its analytical importance, the EFF transitioned from a triennial to a biennial survey cycle starting in 2022, ensuring that the information remains timely and relevant.

Methodology

The 2024 EFF employs a sophisticated sample design aimed at ensuring representativeness across the entire household population, particularly concerning aggregate household wealth. Given the skewed distribution of wealth in Spain, the survey includes an oversampling of high-wealth households. This approach is crucial for accurately analyzing the upper echelons of wealth distribution, which are often underrepresented in standard surveys.

Another notable aspect of the EFF is its longitudinal component. Each wave of the survey interviews both newly selected households and those that participated in previous editions. This system of linked sub-panels enables researchers to track developments in income, wealth, and consumption over time while maintaining the cross-sectional representativeness of the sample.

To balance the need for high-wealth oversampling and the longitudinal aspect with the requirement for cross-sectional representativeness, each wave incorporates a refreshment sample designed by the National Statistics Institute (INE). This meticulous planning ensures that the survey remains a reliable source of data.

The EFF is also part of the Household Finance and Consumption Survey (HFCS) of the Eurosystem, which guarantees methodological consistency and international comparability of results. The questionnaire itself is structured into nine thematic sections, covering demographic characteristics, real and financial assets, debts, insurance, pensions, employment status, income, consumption, and savings.

Data collection primarily occurs through face-to-face household interviews conducted by specially trained interviewers using Computer-Assisted Personal Interviewing (CAPI). This method reflects the complexity and length of the questionnaire, which often requires over an hour to complete, especially in households with intricate wealth structures.

The complexity of the questionnaire presents significant challenges. It encompasses numerous economic and financial variables, many of which are sensitive and involve monetary amounts. This complexity necessitates a high level of cooperation from respondents and the use of advanced data collection tools, along with highly specialized interviewers.

Study Implementation

Since 2011, the EFF has been executed through a collaboration between NORC at the University of Chicago and Verian, under the direction of the Banco de España. NORC leads the project, leveraging its extensive international experience in household finance surveys, including the Survey of Consumer Finances in the United States, which has been administered since 1992.

Verian is tasked with the data collection in Spain, managing a particularly demanding fieldwork operation due to the length and complexity of the interviews, which average around 1.5 hours. Achieving high response rates in a wealth and income survey requires significant operational effort, including the design and implementation of specific fieldwork protocols aimed at minimizing non-response and measurement errors.

To address these challenges, Verian has developed specific procedures for interviewer selection, training, and supervision, along with proprietary tools for fieldwork management, questionnaire review, and data quality control. These tools are tailored to meet the complexity of the study and adhere to the Banco de España’s high-quality standards.

Together, NORC and Verian have successfully conducted the six most recent waves of the EFF (2011, 2014, 2017, 2020, 2022, and 2024), establishing a solid track record in implementing one of the most complex surveys within the Spanish statistical system.

With the recent publication of the 2024 wave results, both organizations are already preparing for the EFF 2026, continuing their collaboration grounded in methodological rigor, fieldwork excellence, and institutional trust.

For those interested in the latest findings, the main results of the Survey of Household Finances 2024 are available on the Banco de España website, providing valuable insights into the financial landscape of Spanish households.